Debugging is a core skill required by programmers, yet we know little about how to effectively teach the process of debugging. The challenges of learning debugging are compounded for novices who lack experience and are still learning the tools they need to program effectively. In this work, we report a case study in which we used a think-aloud protocol to gain insight into the behaviour of three students engaged in debugging tasks. Our qualitative analysis reveals a variety of helpful practices and barriers that limit the effectiveness of debugging. We observe that comprehension, evidence-based activities, and workflow practices all contribute to novice debugging success. Lack of sustained effort, precision, and methodical processes negatively impact debugging effectiveness. We anticipate that understanding how students engage in debugging tasks will aid future work to address ineffective behaviours and promote effective debugging activities.

调试是程序员必备的一项核心技能，但我们对如何有效地教授调试过程知之甚少。对于缺乏经验并且仍在学习有效编程所需工具的新手来说，学习调试的挑战更加复杂。在这项工作中，我们报告了一个案例研究，在该案例研究中，我们使用有声思考协议来深入了解三名从事调试任务的学生的行为。我们的定性分析揭示了各种有用的实践和限制调试有效性的障碍。我们观察到理解、基于证据的活动和工作流实践都有助于新手调试成功。缺乏持续的努力、精确性和有条不紊的过程会对调试效率产生负面影响。